rd pretends to be a device allocated by subr_autoconf. it needs to refcnt_init like a real device too.
rd pretends to be a device allocated by subr_autoconf. it needs to
refcnt_init like a real device too.

found by deraadt@

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars